From: Oskar Schirmer Date: Tue, 12 Nov 2013 15:46:38 +0000 (+0000) Subject: ASoC: fsl: imx-pcm-fiq: omit fiq counter to avoid harm in unbalanced situations X-Git-Tag: v3.13-rc1~2^2~2^2~2^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fc7dc61d9a87011aaf8a6eb3144ebf9552adf5d2;p=pandora-kernel.git ASoC: fsl: imx-pcm-fiq: omit fiq counter to avoid harm in unbalanced situations Unbalanced calls to snd_imx_pcm_trigger() may result in endless FIQ activity and thus provoke eternal sound. While on the first glance, the switch statement looks pretty symmetric, the SUSPEND/RESUME pair is not: the suspend case comes along snd_pcm_suspend_all(), which for fsl/imx-pcm-fiq is called only at snd_soc_suspend(), but the resume case originates straight from the SNDRV_PCM_IOCTL_RESUME. This way userland may provoke an unbalanced resume, which might cause the fiq_enable counter to increase and never return to zero again, so eventually imx_pcm_fiq is never disabled. Simply removing the fiq_enable will solve the problem, as long as one never goes play and capture game simultaneously, but beware trying both at once, the early TRIGGER_STOP will cut off the other activity prematurely. So now playing and capturing is scrutinized separately, instead of by counting. Signed-off-by: Oskar Schirmer Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- Reading git-diff-tree failed